Governor control mechanism



April 7, 1964 c. H. FRICK 3,127,734

GOVERNOR CONTROL MECHANISM Original Filed Dec. 27; 1954 4 Sheets-Sheet 170MAN1/AL ENG/NESPEED 1. El? 60VERNOR IZESPO/VS/VE EOVERNOP @wfl f H 7/if 1 I w /l mam;

April 7, 1964 c. H. FRICK GOVERNOR CONTROL MECHANISM 4 Sheets-Sheet 2Original Filed Dec.

adl iiifii%z-z BY TTO R N E! I I bukvkav lw gm I I l I I I I I l I I I II I I I I I I I I I I L A ril 7, 1964 c. H. FRICK 3,127,734

GOVERNOR CONTROL MECHANISM Original Filed Dec. 27, 1954 4 Sheets-Sheet31 SPEED RESPONS/VE GUVER/VOR 7v MAM/AL fspssp CONT/20L YT l a? 0 il 7?I @Q #9 67 INVENTOR I i [)far ailfikr BY i7 ATTORNEY April 7, 1964 c. H.FRICK 3,127,734

GOVERNOR CONTROL MECHANISM Original Filed Dec. 2'7, 1954 4 sheets sheet4 AIR INTAKE All? INTAKE F/LTEI? /5 FILTER E/VG/NE SPEED RESPONS/VE60VERNOE WAIVSM/SSIO/V 007W? m\/ A: Lad) spa-0 RESPONS/VE 5 GOVERNORVALVE ENG/NE Dk/VEN BLOWEQ FZUID COUPLING/ TRANSMISSION 77PANSM/5S/0NOUTPUT SPEED PESPONS/VE MENU MLVE Inventor Attorney United States PatentThis invention relates to a control mechanism for a power plant and moreparticularly to a control mechanism for a power plant including aninternal combustion engine drivingly connected to a power transmittingmechanism.

This is a continuation consolidating copending applications Serial No.477,809 and Serial No. 477,857, which were filed December 27, 1954, andare now abandoned.

It is one of the principal objects of the invention to provide a powerplant of the type described with an engine fuel supply control mechanismresponsive to the respective speeds of the engine and the driven outputshaft of the power transmitting mechanism and modifying the governedengine speed characteristic to maintain selected speed characteristicsof a driven output shaft of the power transmitting mechanism withvariations in the application of load.

The invention has particular application to an internal combustionengine power plant in which the driven out put shaft of the powertransmitting coupling mechanism has droop characteristics under loaddiffering from those of the engine such as in the case withtorque-converter and eddy-current type couplings. In such power plants,the rate of operation of the engine tends to decrease with increasedapplication of load and the rate of operation of the output shaftfurther tends to decrease relative to the rate of operation in theengine due to the slippage characteristics of such couplings. Thesecharacteristics result in an accumulative reduction in the poweravailable at the output shaft. The invention is not limited to powerplants of this particular type, however, being considered applicable tointernal combustion engine power plants including power transmittingmechanisms generally to modify the droop characteristics of the engineupon application of load thereby increasing the power available at theoutput shaft.

Among the several primary objects of the invention are to provide apower plant of the type described with control mechanism including anengine speed-responsive governor and an output shaft speed-responsivegovernor which are cooperatively interconnected to modify the operationof a fuel supply mechanism to maintain a desired output shaft speed; toprovide such a power plant with a control mechanism including an enginespeedresponsive governor and an output shaft responsive governor whichare cooperatively interconnected to modify the operation of an enginefuel supply mechanism and having a manual control for varying thespeed-responsive action of one of the governors thereby varying theselected output shaft speed at which the power plant is governed; and toprovide such a power plant with a control mechanism including a fuelsupply control mechanism, a variable-speed governor mechanism responsiveto the speed of the engine and operably connected to the fuel controlmechanism to control the fuel supply and thereby the speed of theengine, and a second governor responsive to the speed of the outputshaft of the power transmitting mechanism and operable to modify theengine speed-responsive characteristic or fuel supply controlling actionof the first governor.

With regard to a first illustrative embodiment herein- 3,127,734Patented Apr. 7, 1964;

after shown and described, certain further and more specific objects ofthe invention are to provide a power plant of the type described with anengine fuel supply control mechanism controllable by an enginespeed-responsive governor and having a variable-speed governorresponsive to the speed of the power transmitting output shaft andoperatively connected to modify the fuel-controlling operation of theengine governor to maintain a desired output shaft speed; to providesuch a power plant with a control mechanism including a fuel controlmember, a variable-speed governor mechanism responsive to the speed ofthe engine and operably connected to the fuel control member to controlthe speed of the engine, and a second variable-speed governor responsiveto the speed of the power transmitting output shaft and operable to varythe engine speed responsive characteristic or setting and thus the fuelsupply controlling action of the first governor to maintain a selectedoutput shaft speed; and to provide a power plant including an internalcombustion engine and a power transmitting mechanism having inherentslippage characteristics with a fuel control mechanism including a fuelsupply control member, a variable-speed vacuum governor responsive tosub-atmospheric pressure existing in a portion of the engine air intakesystem and operably connected to the fuel control member to control thefuel supply and thereby the speed of the engine, and an output-shaftdriven variable-speed centrifugal governor operable to control thesub-atmospheric pressure existing in the portion of the intake systemwhich is applied to the vacuum governor thereby maintaining the selectedoutput shaft speed.

With regard to a second illustrative embodiment, certain further andmore specific objects of the invention are to provide a power plantincluding an internal combustion engine and a power transmittingmechanism having inherent slippage characteristics with a controlmechanism including a fuel supply control mechanism, a manuallycontrolled variable-speed governor mechanism responsive to the speed ofthe engine and operably connected to the fuel control mechanism tocontrol the fuel supply and thereby the speed of the engine, and asecond governor responsive to the speed of the output shaft of the powertransmitting mechanism and operable to modify the enginespeed-responsive characteristic and fuel supply controlling action ofthe first governor to maintain the selected output shaft speed; and toprovide such a power plant with a control mechanism comprising a fuelcontrol mechanism which is operably connected to and controlled by avariable-speed vacuum governor, the vacuum governor being responsive toan engine speed indicative of sub'atmospheric pressure existing in aportion of the engine intake manifold and including a manuallycontrolled valve in the intake operable to vary the engine speedindicative pressure signal applied to the vacuum governor and therebythe engine speed maintaining characteristic thereof, and an output shaftdriven speed-sensitive variable orifice governor modifying theapplication of the sub-atmospheric intake manifold pressure to thevacuum governor to modulate the fuel controlling action of the vacuumgovernor to thereby maintain the desired output shaft speed as initiallyse ected by the positioning of the manual valve.

The foregoing and other objects, advantages and features of theinvention will be more thoroughly understood from the followingdescription of the several illustrative embodiments having reference tothe accompanying drawings, in which:

FIGURE 1 is a diagrammatic view in side elevation of an internalcombustion engine power plant embodying a first form of controlmechanism constructed in accordance with the invention;

FIGURE 2 is a view showing certain details of a portion of the controlmechanism of FIGURE 1 and is taken substantially on the line 2-2 ofFIGURE 1;

FIGURE 3 is an enlarged detailed view of a portion of FIGURE 1 withportions thereof broken away and in section;

FIGURE 3a is an enlarged detailed view of another portion of FIGURE 1and is complementary to that portion shown in FIGURE 3;

FIGURE 4 is a View complementary to FIGURE 2 and shows a portion of thecontrol mechanism of FIG- URE 1 with portions thereof broken away and insection;

FIGURE 5 is a diagrammatic view similar to FIGURE 1 and shows aninternal combustion engine power plant embodying a second formof controlmechanism constructed in accordance with the invention; and

FIGURE 6 is an enlarged view of a portion of FIG- URE 5 with partsbroken away and in section.

Referring more particularly to the drawings, FIGURE 1 shows a powerplant including an internal combustion engine 10 which for illustrativepurposes is shown as a two-cycle diesel engine. The crankshaft 11 of theengine is drivingly connected to a power transmitting mechanism 12including a fluid coupling, such as a torque converter, and an outputshaft 14 driven by the engine through the coupling.

The combustion air intake system for the engine includes a Y-shapedcoupling member 18 having an air receiving chamber 20 therein which isconnected to the outlets of a pair of air filter units 16 which aremounted in parallel by the upper branches of the member 18. The outletof the air receiving chamber 26 is connected through an air flow controlvalve mechanism 22 to the inlet 23 of an engine driven blower 24 of apositive-displacement type such as a Roots blower. The outlet of theblower, not shown, is connected to the scavenging air box of the engine,also not shown. The blower is drivingly connected to the engine at 15through the power transmitting mechanism 12.

As shown by FIGURE 3, the air flow control valve mechanism 22 comprisesa body member 25 having a main passage 26 and a secondary venturi bypasspassage 38, both of which serve to connect the air receiving chamber 20to the blower inlet 23. The main passage 26 is controllable by abutterfly valve 23 mounted on a shaft 30 which is journaled in the valvebody transversely of the main passage. The ends of the shaft 30 projectexternally of the body member 25 and an air valve stop cam 32 secured toone end of the shaft is provided with two projecting lug portions 32aand 32b which contact two adjustment screws 34 and 36, respectively,threadably mounted in a flange portion 37 formed on the body member 25to provide angular idle and maximum engine speed limits for the closingand opening, respectively, of the air valve 28. A lever 40 secured tothe opposite end of the shaft 30 forms a crank arm which is pivotallyconnected at 42 to a link 44 which is operable, as described in detailbelow, to control the operation of the valve 28.

Air flow in the venturi passage 38 develops a sub-atmospheric depressionof air pressure at its throat proportional to the engine or blowerintake vacuum as determined by the speed of the engine and the positionof the air flow control valve 28. This sub-atmospheric pressurecondition at the venturi throat is applied through a bleed passage 64and a conduit 65 to one end of a housing 66 mounted on the cylinder head67 by the bracket 63; the two ends of the housing being separated by aflexible diaphragm or piston member 6. The opposite end of the housing66 is perforated at 70 thereby subjecting the opposite side of thediaphragm to atmospheric pressure and providing an opening for a link'71 which operably interconnects the diaphragm 69 with the upper end ofa fuel control lever 72. As best seen in FIGURE 4, the lever 72 ispivotally supported by a bracket 76 and is connected at its lower end toan axially movable fuel control member 73, such as an injector controlrack, by a pin-and-slot connection 74. A helical spring 75 istorsionally interposed between the bracket 76 and the lower portion ofthe lever '72 and biases the lever 72 and the fuel control member 73 ina fuel-increasing direction in opposition to the tendency of the vacuumapplied to the diaphragm to move these elements in a fuel-decreasingdirection.

During normal operation there is no mechanical connection providedbetween the air valve 28 and the control lever 72. However, a connectinglinkage is provided, as shown in FIGURES 1, 2, 3 and 4 for normallyreleasing a leaf-type buffer spring 45 from biasing engagement with theupper end of control lever 72 except when the air valve 28 is in itsengine idle position. When the air valve 28 is in its idle position, thebuffer spring 45 is moved into biasing engagement with the lever 72, andits biasing effect is effectively added to the fuel-increasing biasingaction in opposition to the increased engine vacuum thereby maintainingengine operation above stall speed. This linkage includes a shaft 46which is pivotally mounted in the cylinder head 67. The end of thebuffer spring 45 is suitably attached to the shaft 46. A lever 47 isalso secured to the shaft 46, the upper portion of which is providedwith a pin 48 engageable with and causing the lower portion of the lever72 to carry the fuel control member 73 to a fuel off or engine shutdownposition when the shaft 46 is rotated in a counterclockwise direction. Abell-crank lever 49 is mounted on the end of the shaft 46 which projectsoutwardly from the cylinder head, and a manually operable link 50pivotally connected at 51 to the lower arm of this lever serves torotate the lever 49, the shaft 46, and the lever 47 in acounterclockwise direction causing the pin 48 to move the lever 72 tomove the member 73 to a fuel-01f position and thus obtain engineshutdown. The other arm of the lever 46 is pivotally connected at 52 toone end of an adjustable turnbuckle link 53. The other end of the link53 is pivotally connected at 54 to an arm of a lever 55. The lever 55 ispivotally mounted on a shaft 56 which is supported by a bracket 57mounted on the rear of the engine block 63. An operating lever 58 isalso pivotally mounted on the shaft 56 in axially spaced relation to thelever 55. This lever 58 is provided with a pivotal connection at 59 withthe air flow control valve operating link 44 and is operable, asdiscussed in detail below, to vary the opening of the control valve 28thereby controlling the engine or blower intake vacuum and,consequently, the sub-atmospheric application of pressure to thediaphragm 69. When the operating lever 58 is rotated counterclockwise toits engine idle position moving the valve 2% to its closed position, apickup flange 60 formed on the operating lever 55 engages a similarcoacting flange 61 formed on the lever 55 causing the lever 55 to rotatein a counterclockwise direction. This counterclockwise rotation of thelever 55 is transmitted through the link 53, the lever 49, and the shaft46, rotating the spring 45 into biasing engagement with the lever 72thereby establishing and maintaining engine idle speed.

It will be noted that the above-described combination of an air flowcontrol valve mechanism and a fuel-con trolling diaphragm mechanismconstitutes a conventional fuel control mechanism of the variable-speedvacuumgovernor type which is responsive to the speed of the engine ascontrolled by any given setting of the air valve 28. The structure andoperation of this engine speed responsive governor is shown anddescribed in somewhat greater detail in United States Patent No.2,617,396 to Charles E. Ervin, Jr.

Assuming a fixed position of the air valve 28, a momentary decrease inengine speed results in decreased air flow through the venturi with aconsequent drop in the vacuum force applied to the diaphragm 58. Thislessened diaphragm actuating force allows the torsional spring 75 torotate the lever '72 in a fuel-increasing direction; a movementtransferred to the individual injectors by the am'ally movable member'73. This fuel-increasing movement will continue until a new conditionof balance is achieved between the spring and vacuum forces. Conversely,a momentary increase in engine speed will result in greater venturi airflow with the consequent application of a greater vacuum force on thediaphragm tending to rotate the lever '72 in a fuel-decreasing directionuntil a condition of balance is again attained between the spring anddiaphragm forces. With such a governor, assuming constant loadconditions, the engine speed is controlled by the position of the airvalve 23. By opening the air valve, the air velocity through the venturiis reduced, consequentially decreasing the fuel-decreasing vacuum forceon the diaphragm and allowing the control spring to increase fueldelivery until a balanced condition is reached thereby establishing ahigher governed engine speed. Conversely, closing of the air valve froma given position serves to increase the venturi how, and the resultingincreased vacuum force applied to the diaphragm decreases fuel deliveryto bring about a new balanced condition at a lower governed enginespeed. The control valve 28 thus serves to adjust the speed controllingaction or speed responsive characteristic of the engine governor bycontrolling the engine or blower intake vacuum and consequently thesub-atmospheric pressure applied to the vacuum governor diaphragm 69.

In the forms of the invention shown in FIGURES 1-4, the control valve 23is connected to a variable-speed governor 130 which is responsive to thespeed of the power transmitting output shaft 14. As best shown in FIGURE3a, the governor 131) comprises a housing 132 which is suitably mountedon the rear of the power transmitting mechanism 12 by a bracket 134. Ashaft 136 is rotatably journaled within the housing 132 and a pulley 138secured to one end thereof is drivingly connected to a pulley 140secured to the output shaft 14- by a belt 142. A conventionalcentrifugal fiyball governor mechanism, not shown, is mounted on theshaft 136 within the housing 132 and is operably connected by suitablemeans, also not shown, to rotate a shaft 144 journaied in the housingtransversely to the shaft 136 in a clockwise direction as the fiyweightsare caused to move outwardly in response to the speed of the outputshaft. A lever 146 pivotally mounted at 143 by a bracket 151? secured tothe housing 132 is provided with a downwardly extendin arm which ispivotally connected at 152 to a manually operable control link 154. Thecontrol link 1 may be shifted remotely by suitable accelerator controllinkages, not shown. The lever 1426 is provided with two lugs which areengageable with screws 18?. and 134 threadably mounted in the bracket 1%to form stops limiting the pivotal movement of the lever 146. A secondarm on the lever 146 includes a lateral projection 1% which mounts athreaded eye-bolt 153, the adjusted position of which is locked by nuts169 and 162. One end 164 of a tension-type speeder spring 166 is securedto the eye of the eyebolt 158 and the other end 168 of the speederspring is secured intermediate the ends of a lever 17%, one end of whichis rigidly secured to the speed-responsive shaft 14 The opposite end ofthe lever 17 i) is pivotally connected at 172 to one end of a floatinglink 174- which is pivotally connected at its other end to the operatinglever 58 as indicated at 178.

The links 17 and 44 are provided with threadable axial adjustment at 176and 43, respectively, intermediate their ends and the pivotal connection178 is adjustable by means of the slot 130 as shown, or by othersuitable means to vary the effective length of the lever 58 about itspivot 56. The provided adjustments in the control linkages make itpossible to vary the modifying action of the output shaft governor onthe engine operation to achieve the desired engine and output shaftoperating characteristics.

As shown in FIGURES 3 and 3a, the various components of the controlsystem are in idle position. In operation when the control link 154 ismoved to the left in an engine speed-increasing direction, the lever 146is rotated in a clockwise direction increasing the biasing effect of thespeeder spring on the lever in opposition to the tendency of thecentrifugal flyweights to move outwardly in response to the speed of theoutput shaft. This increased biasing effect results momentarily in thecollapse of the flyweights permitting the rotation of the shaft 144 andthe lever 170 in a counterclockwise direction. This movement isconsequentially transferred to the link 1'74, the operating lever 58,the link 44, and the control valve lever 40 thereby rotating the controlvalve 23 in an opening direction. The movement of the operating lever 53also releases the idle buffer spring 45 out of biasing engagement withthe lever 72 as explained above. The opening of the control valve 28reduces the air flow through the venturi passage 38 and the amount ofvacuum applied to the diaphragm 69. This permits the torsional spring'75 to move the lever '72 and the fuel control member '73 in afuel-increasing direction with resultant increases in the operatingrates of the engine and the output shaft 14.

When the speed of the output shaft 14 is again sufficient to move theilyweights outwardly against the biasing effect of the speeder spring166, the lever 170 will be rotated slightly in a clockwise directionuntil a balance is achieved between the biasing effect of the spring andthe centrifugal forces acting on the flyweights and consequentialclosing movements of the control valve 28 occurs until a new balance isachieved between the vacuum being applied to the diaphragm and thebiasing effect of the spring 75. The components of the control systemwill act in a similar manner when load is applied to the output shaft 14momentarily resulting in a decrease in the output shaft speed from thedesired level as determined by the position of the lever 1%. Theconverse operation will occur between the various components of thecontrol system when the control link 15 3 is moved in a speed-decreasingdirection or when load is removed from the output shaft momentarilyresulting in a higher output shaft speed relative to the setting of thelever 146; the resulting outward movement of the flyweights causing theshaft 144 and lever 17-9 to be rotated in a counterclockwise directionthereby moving the control valve 28 in a closing direction until a newbalance is achieved between the biasing components of both governors. Itwill thus be seen that the variable-speed output shaft governor modifiesthe engine or blower intake vacuum to maintain the speed of the outputshaft at a relatively constant value with both increasing or decreasingapplications of load.

In the form of the invention shown in FIGURES 5 and 6, the engine speedresponsive vacuum. governor is essentially the same as that shown anddescribed with reference to FIGURES 1-4 except for its engine speedmodifying connection to the transmission output speed responsivegovernor. To avoid needless drawing duplication, however, the engineshutdown control partially shown in the drawings of the now abandonedparent application S.N. 477,857 has been omitted in FIGURE 5. Aspreferably associated with the vacuum valve controlling link 44, thisshutdown control is adequately disclosed in FIGURES 2 and 4 as describedabove. Hence, the engine governor of this embodiment need not be shownand described in great detail, like reference numerals having been usedto identify the same governor components.

In the embodiment of FIGURES 5 and 6, the engine speed responsivecharacteristic of the vacuum governor is initially established by manualadjustment of the valve 28 to provide a desired output shaft speed. Tomaintain this desired shaft speed with variations in load, the operationor speed responsive characteristic of the vacuum governor is modified bya variable orifice governor 78 which bleeds air into the conduit 65 inaccordance with the output shaft speed thereby modulating thefueldecreasing application of engine vacuum to the diaphragm 69. Thegovernor 78 comprises a housing 82 mounted to the rear of the powertransmitting mechanism 12 by the bracket 80. As shown in FIGURE 6, thehousing 82 has an air inlet chamber 84 connected by a conduit 86 to theair receiving chamber 20 and having an outlet chamber 87 connected by aconduit 88 to the conduit 65. By connecting the chamber 84 to thechamber 20 rather than directly to the atmosphere, filtered air at anintermediate sub-atmospheric pressure is utilized in the reduction ofthe engine speed proportional vacuum at the venturi throat which isbeing applied to the diaphragm. A variable orifice assembly 89 isrotatably mounted within the chamber 84 and includes a carrier member 90having two diametrically opposed radial portions extending transverselyof the chamber 84 and two axially extending shaft portions journaled inbearings 92 and 94. A cup-shaped insert 96 mounted in a counterbore 98formed in one of the radial portions of the carrier member is providedwith a radial port or orifice 100, the effective size of which iscontrolled by a valve member 102 reciprocably mounted within thecup-shaped insert. A spring 104 mounted within a bore 106 coaxial withthe counterbore 98 and the radial portions of the member 90 serves tobias the valve member 102 in an orifice-open position in opposition tothe speed-responsive centrifugal forces tending to move the valve member102 radially outwardly in an orifice-closing direction; the spring 104being connected at one end to the valve member and at its opposite endto a member 108 which is threadably mounted in another counterbore 109formed in the radial portion of the member 90 opposite the orificecarrying portion. A bore 110 provided in one of the axially extendingshaft portions of the carrier member interconnects the bore 106 with theoutlet chamber 87. The other axially extending shaft portion of themember 90 is provided with a transverse key-and-slot connection 112 withone end of a stub shaft 114. The stub shaft 114 is rotatably journaledin a bearing 116 carried by the bracket 80. A pulley 118 is connected tothe opposite end of shaft 114 and is drivingly connected by a belt 122to a pulley 120 mounted on the fluid coupling output shaft.

In operation the variable orifice output shaft governor is set so thatthe orifice just closes at the desired maximum no-load output shaftr.p.m. This is accomplished by varying the rate of the spring 104 byadjustment of the member 108 through a plug opening 111 provided in thehousing member 82. The maximum-speed limit screw 36 for the butterflyvalve 28 controlling the engine speed-responsive vacuum governor is alsoadjusted to give the desired maximum no-load output shaft speed.Assuming the valve 28 in its maximum speed or wide open position, asload is applied to the output shaft the speed of the output shaft istemporarily reduced consequentially reducing the centrifugal forcesacting on the variable orifice valve 102. This causes the valve 102 toopen to a degree dependent upon the reduction in output shaft speed witha proportional bleeding of air to reduce the venturi-generated vacuumapplied to the diaphragm. The torsion spring 75 of the vacuum governorwill then tend to move the lever 72 to an increased-fuel position untila new balance is established between the control spring and thediaphragm action on the control lever. This results in a gradualincrease in the engine speed tending to maintain the converter outputshaft speed constant with increasing load until the full power output ofthe engine is reached. The converse will occur with decreasing loads.Similarly, at intermediate settings of the control valve 28, thetendency of the orifice valve 102 to further open or close with areduction or increase, respectively, in output shaft speed will serve tomaintain the speed of the output shaft at a constant value withincreased or decreased application of load.

From the foregoing description, it will be apparent that theabove-described embodiment of the power plant control or governingsystem of the illustrative embodiments are applicable to internalcombustion engine power plants generally to modify the load droopcharacteristics. In power plants utilizing couplings of a type havinginherent slippage characteristics, use of such a governing systemprovides for a relative increase in engine speed with increase in loadwhich will consequentially serve to maintain the rate of operation ofthe output shaft at a substantially constant value. Such operationpermits higher engine power output at more eflicient points of operationfor both the engine and the coupling.

While only two specific embodiments of the invention have been shown anddescribed for the purposes of illustration, it is appreciated thatvarious modifications may be made therefrom without departing from thespirit and scope of the invention as defined in the following claims.

I claim:

1. In a power plant including an engine and a power transmittingmechanism driven thereby, said power transmitting mechanism including anoutput shaft drivingly connectable to a variable load and havingoperating characteristics whereby the speed of the output shaft tends todecrease with the application of load thereto more rapidly than thespeed of the engine: a control mechanism comprising fuel supply meansfor supplying variable amounts of fuel to the engine and including acontrol member movable between an off position in which it conditionssaid supply means to substantially cut off the supply of fuel to theengine, an intermediate position in which it causes fuel to be suppliedto the engine at a restricted rate permitting said engine to operate ata low idling speed, and an open position in which it conditions saidfuel supply means to supply fuel to the engine at a maximum rate, meansfor normally biasing said fuel supply control member toward its openposition, means responsive to the speed of the engine and operablyconnected to actuate said fuel supply control member in a decreasingfuel direction between said open and intermediate fuel supplycontrolling positions in opposition to said biasing means to vary theengine fuel supply in accordance with deviations from a selectivelyestablished engine speed to maintain such established engine speed, saidengine speed responsive means including means for selectivelyestablishing the engine speed from which deviations render said enginespeed responsive means effective to actuate said fuel supply controlmember, means responsive to the speed of the output shaft and includingan output member movable in response to deviations from a selectivelyestablished speed of said output shaft, a control element movablethrough an operating zone between a first and second position andoperably connected to selectively establish the output shaft speed fromwhich deviations effect movement of said output member, and meansoperably connecting said engine speed selecting means to the outputmember of said output shaft speed responsive means, whereby said fuelsupply control memher is actuated alternatively in a fuel increasing ordecreasing direction by said biasing and engine speed responsive meansbetween said intermediate and open fuel supply controlling positions inaccordance with actuation of said engine speed selecting means by saidshaft speed responsive output member indicating respectively adecreasing or increasing speed deviation from the selectivelyestablished output shaft speed to thereby maintain the output shaftspeed selectively established by the positioning of the output shaftspeed control element in said operating zone.

2. In a power plant including an engine and a power transmittingmechanism driven thereby, said power transmitting mechanism including anoutput shaft drivingly connectable to a variable load, and saidmechanism having operating characteristics whereby the speed of saidoutput shaft tends to decrease with the application of load to saidoutput shaft more rapidly than the speed of said engine decreases: acontrol mechanism comprising fuel supply means for supplying variableamounts of fuel to said engine and including a control member movablebetween an off position in which it conditions said supply means tosubstantially cut off the supply of fuel to said engine, an intermediateposition in which it causes fuel to be supplied to said engine at arestricted rate permitting said engine to operate at a low idling speed,and an open position in which it conditions said fuel supply means tosupply fuel to said engine at a maximum rate, means for normally biasingsaid fuel supply control member toward its open position, meansresponsive to the speed of said engine and operable in accordance withdeviations from a selectively established engine speed to actuate saidfuel supply control member in a decreasing fuel direction between saidopen and intermediate fuel supply controlling positions in opposition tosaid biasing means to vary the engine fuel supply so as to maintain suchestablished engine speed, said engine speed responsive means includingan element movable through an operating zone between a first positionand a second position to selectively establish the engine speed to bemaintained by said engine speed responsive means, and means responsiveto the speed of said output shaft and including a power output memberoperably connected to adjust the position of said speed establishingelement in said operating zone to change the engine speed maintained bythe fuel supply regulating operation of said engine speed responsivemeans and thereby maintain said load driving output shaft at a desiredconstant speed.

3. In a power plant including an engine and a power transmittingmechanism driven thereby, said power transmitting mechanism including anoutput shaft drivingly connectable to a variable load, and saidmechanism having operating characteristics whereby the application ofload tends to decrease the speed of said output shaft more rapidly thanthe speed of said engine decreases: a control mechanism comprising fuelsupply means for supplying variable amounts of fuel to said engine andincluding a control member movable between an off position in which itconditions said supply means to substantially cut off the supply of fuelto said engine, an intermediate position in which it causes fuel to besupplied to said engine at a restricted rate permitting said engine tooperate at a low idling speed, and an open position in which itconditions said fuel supply means to supply fuel to said engine at amaximum rate, means for normally biasing said fuel supply control membertoward its open position, means responsive to the speed of said engineand operably connected to actuate said fuel supply control memberbetween said open and intermediate fuel supply positions in oppositionto said biasing means to maintain a selectively established enginespeed, said engine speed responsive means including a control elementmovable through an operating range between first and second positions toestablish the engine speed to be maintained by the fuel supplycontrolling action of said engine speed responsive means, meansresponsive to the speed of said output shaft and including a poweroutput member operably connected to actuate the control element of saidengine speed responsive means to adjust the engine speed to bemaintained by the fuel supply controlling action of said engine speedresponsive means and thereby the engine driven speed of said outputshaft in response to deviations from a selectively established outputshaft speed, and a manually operable element movable through anoperating zone between a first position and a second position andoperably connected to selectively established the output shaft speed tobe maintained by operation of said last-mentioned means in accordancewith the movement of said manually controlled element in said operatingzone.

4. A control mechanism for a power plant including an engine and a powertransmitting mechanism including an output shaft drivingly connectedtherethrough to said en gine, said control mechanism comprising meansfor controlling the fuel supply to the engine, means responsive to thespeed of said engine and operably connected to modify the fuel supplyingfunction of said fuel supply means to maintain the engine at a selectedconstant speed, means for varying the selected constant engine speedmaintained by the fuel supply controlling operation of said engine speedresponsive means, means responsive to the speed of said output shaft andincluding a power member operably connected to actuate said lastmentioned means to vary the selected engine speed maintained by the fuelsupply controlling action of said engine speed responsive means inaccordance with variations in the speed of the output shaft to therebymaintain the output shaft at a selected constant speed, and said outputshaft speed responsive means including a control element operablyconnected and selectively movable through a range to establish theconstant output shaft speed maintainable by speed responsive movement ofthe power member of said output shaft speed responsive means.

5. A control mechanism for a power plant including an engine, a powertransmitting coupling drivingly connected to said engine and an outputshaft driven through said coupling, said coupling having load-speeddroop characteristics differing from those of said engine, said controlmechanism comprising an engine fuel regulating member, an engine airsupply means including a main passageway, a valve movable between openedand closed positions to modify engine intake air flow through said mainpassageway, and a venturi bypassing said valve and in parallel with themain passageway, said venturi being effective to cause a subatmosphericdepression proportional to the engine intake air flow passingtherethrough and indicative of engine speed for any given position ofsaid valve, piston means connected to and responsive to the engine speedindicating subatmospheric depression of air in said venturi and operablyconnected to actuate the fuel regulating member to maintain said engineat a constant. speed corresponding to the position of said valve, andmeans responsive to the speed of said output shaft and including a poweroutput member operatively connected to actuate said valve between itsopened and closed positions to modulate the engine intake air llow insaid main passage and venturi to cause said piston means to actuate thefuel regulating member to compensate for changes in the speed of saidoutput shaft thereby maintaining said output shaft at a desired constantspeed.

6. In a control mechanism for a power plant including an engine and afiuid coupling including an output shaft drivingly connectable to saidengine, an engine combustion air receiving chamber having an outlet,means for conducting air to the engine from said outlet including a mainpassage, a valve movable between opened and closed positions controllingsaid main passage, and a venturi bypassing said valve and effective tocause a subatmospheric air pressure proportional to the engine intakeair flow passing therethrough and indicative of engine speed for anygiven position of said valve, means including a fuel control membermovable in opposite directions to increase and decrease the engine fuelsupply, a pivoted two-arm lever having one arm drivingly connected tosaid fuel control member, resilient means biasing said lever in afuel-increasing direction, an air cylinder having one end incommunication with the atmosphere and its other end closed to theatmosphere and in communication with said venturi, a flexible diaphragmseparating the respective ends of said air cylinder and drivinglyconnected to the other arm of said lever, and governor means responsiveto the rate of operation of said output shaft and including a speedresponsive power output member operably connected to vary the effectiveopening of said valve in accordance with deviations from a desiredselectively established output shaft speed thereby controlling theengine fuel supply to maintain the desired engine driven output shaftspeed.

7. In a control mechanism as set forth in claim 6, said output shaftresponsive governor means comprising a speed responsive mechanism drivenby said output shaft, said output member being movable by said speedresponsive mechanism to actuate said valve between its opened and closedpositions in accordance with decreasing and increasing speed deviationsfrom the desired output shaft speed, and manually operable control meansincluding a control element movable through a control range to modifythe speed setting response of said speed responsive mechanism toestablish the desired output shaft speed.

References Cited in the file of this patent UNITED STATES PATENTS Baueret al. July 19, 1932 .Bolli Apr. 23, 1946 Ervin Nov. 11, 1952 Orton Feb.17, 1953 Parker Nov. 3, 1953 Zuhn et a1 Oct. 18, 1955 Worth Dec. 20,1955 FOREIGN PATENTS ltaly Dec. 29, 1951 Sweden Oct. 17, 1944

1. IN A POWER PLANT INCLUDING AN ENGINE AND A POWER TRANSMITTINGMECHANISM DRIVEN THEREBY, SAID POWER TRANSMITTING MECHANISM INCLUDING ANOUTPUT SHAFT DRIVINGLY CONNECTABLE TO A VARIABLE LOAD AND HAVINGOPERATING CHARACTERISTICS WHEREBY THE SPEED OF THE OUTPUT SHAFT TENDS TODECREASE WITH THE APPLICATION OF LOAD THERETO MORE RAPIDLY THAN THESPEED OF THE ENGINE: A CONTROL MECHANISM COMPRISING FUEL SUPPLY MEANSFOR SUPPLYING VARIABLE AMOUNTS OF FUEL TO THE ENGINE AND INCLUDING ACONTROL MEMBER MOVABLE BETWEEN AN OFF POSITION IN WHICH IT CONDITIONSSAID SUPPLY MEANS TO SUBSTANTIALLY CUT OFF THE SUPPLY OF FUEL TO THEENGINE, AN INTERMEDIATE POSITION IN WHICH IT CAUSES FUEL TO BE SUPPLIEDTO THE ENGINE AT A RESTRICTED RATE PERMITTING SAID ENGINE TO OPERATE ATA LOW IDLING SPEED, AND AN OPEN POSITION IN WHICH IT CONDITIONS SAIDFUEL SUPPLY MEANS TO SUPPLY FUEL TO THE ENGINE AT A MAXIMUM RATE, MEANSFOR NORMALLY BIASING SAID FUEL SUPPLY CONTROL MEMBER TOWARD ITS OPENPOSITION, MEANS RESPONSIVE TO THE SPEED OF THE ENGINE AND OPERABLYCONNECTED TO ACTUATE SAID FUEL SUPPLY CONTROL MEMBER IN A DECREASINGFUEL DIRECTION BETWEEN SAID OPEN AND INTERMEDIATE FUEL SUPPLYCONTROLLING POSITIONS IN OPPOSITION TO SAID BIASING MEANS TO VARY THEENGINE FUEL SUPPLY IN ACCORDANCE WITH DEVIATIONS FROM A SELECTIVELYESTABLISHED ENGINE SPEED TO MAINTAIN SUCH ESTABLISHED ENGINE SPEED, SAIDENGINE SPEED RESPONSIVE MEANS INCLUDING MEAND FOR SELECTIVELYESTABLISHING THE ENGINE SPEED FROM WHICH DEVIATIONS RENDER SAID ENGINESPEED RESPONSIVE MEANS EFFECTIVE TO ACTUATE SAID FUEL SUPPLY CONTROLMEMBER, MEANS RESPONSIVE TO THE SPEED OF THE OUTPUT SHAFT AND INCLUDINGAN OUTPUT MEMBER MOVABLE IN RESPONSES TO DEVIATIONS FROM A SELECTIVELYESTABLISHED SPEED OF SAID OUTPUT SHAFT, A CONTROL ELEMENT MOVABLETHROUGH AN OPERATING ZONE BETWEEN A FIRST AND SECOND POSITION ANDOPERABLY CONNECTED TO SELECTIVELY ESTABLISH THE OUTPUT SHAFT SPEED FROMWHICH DEVIATIONS EFFECT MOVEMENT OF SAID OUTPUT MEMBER, AND MEANSOPERABLY CONNECTING SAID ENGINE SPEED SELECTING MEANS TO THE OUTPUTMEMBER OF SAID OUTPUT SHAFT SPEED RESPONSIVE MEANS, WHEREBY SAID FUELSUPPLY CONTROL MEMBER IS ACTUATED ALTERNATIVELY IN A FUEL INCREASING ORDECREASING DIRECTION BY SAID BIASING AND ENGINE SPEED RESPONSIVE MEANSBETWEEN SAID INTERMEDIATE AND OPEN FUEL SUPPLY CONTROLLING POSITIONS INACCORDANCE WITH ACTUATION OF SAID ENGINE SPEED SELECTING MEANS BY SAIDSHAFT SPEED RESPONSIVE OUTPUT MEMBER INDICATING RESPECTIVELY ADECREASING OR INCREASING SPEED DEVIATION FROM THE SELECTIVELYESTABLISHED OUTPUT SHAFT SPEED TO THEREBY MAINTAIN THE OUTPUT SHAFTSPEED SELECTIVELY ESTABLISHED BY THE POSITIONING OF THE OUTPUT SHAFTSPEED CONTROL ELEMENT IN SAID OPERATING ZONE.